Delta IV Lofts New GPS Satellite

A ULA Delta IV lifted off from Cape Canaveral Air Force Station’s Space Launch Complex-37 Thursday evening at 8:59 p.m. Carried to orbit at 11,000 nautical miles and an inclination of 55 degrees was a 3,534 lb. Global Positioning System 2F satellite. The Boeing built spacecraft will take its place in the 31 satellite fleet, which will also include 6 older, semi-retired “birds” as on-orbit spares.

Yesterday’s launch, the 25th of a Boeing Delta IV came after months of delay rising from uncertainty in determining the root cause of an underperforming upperstage RL-10B-2 engine in a similar launch in October 2012. Although ULA has maintained a sterling launch success record, that particular flight was a very close call, and had it not happened to be carrying a relatively lightweight GPS satellite would have likely resulted in either a failure, or a spacecraft deposited in lower than intended orbit, requiring use of on-board propellants for correction.

Although the Delta IV conducted its maiden flight carrying a commercial payload, Eutalsat W5 on 11/20/2002, it was pulled from the market the next year, and has not returned.